Motif

A motif is "any distinctive feature, element, or idea that recurs throughout a story," and it often helps develop "larger narrative elements such as the story's themes or mood." The article's working rule: "a theme is abstract and a motif is concrete." The green light in The Great Gatsby, the flute in Death of a Salesman, the blood and hand-washing imagery of Macbeth: details repeated until a pattern of meaning forms around them. Symbolism is usually expressed through motifs rather than being a separate category, and anything can carry one: an image, a phrase, a sound, a structural or stylistic device.

The motif is the concrete handle on a theme: pick the object or image early, then let recurrence do the arguing. It is the inside-the-story cousin of the trope, which recurs across works rather than within one. In a serial, log motifs in the story bible; one dropped in chapter three and forgotten by chapter fifty is just a loose thread.